Li et al. BMC Neurology (2016) 16:140 DOI 10.1186/s12883-016-0666-4
RESEARCH ARTICLE
Open Access
Early consciousness disorder in acute ischemic stroke: incidence, risk factors and outcome Jie Li1,2†, Deren Wang1† , Wendan Tao1, Wei Dong1, Jing Zhang1, Jie Yang3 and Ming Liu1*
Abstract Background: Little is known about the incidence and risk factors of early consciousness disorder (ECD) in patients with acute ischemic stroke, or about how ECD may affect complications and outcomes. Methods: Patients admitted to our hospital within 24 h of onset of acute ischemic stroke were consecutively enrolled. ECD was evaluated clinically and using the Glasgow coma scale. Multivariate analysis was used to identify risk factors of ECD, as well as associations between ECD and clinical outcomes. Results: Of the 569 patients enrolled, 199 (35 %) had ECD. Independent risk factors of ECD were advanced age (OR 1. 027, 95 % CI 1.007 to 1.048), National Institutes of Health Stroke Score on admission (OR 1.331, 95 % CI 1.257 to 1.410), and massive cerebral infarct (OR 3.211, 95 % CI 1.642 to 6.279). ECD was associated with higher frequency of strokerelated complications (83.4 % vs. 31.1 %, P < 0.001) and higher in-hospital mortality (17.1 % vs. 0.5 %, P < 0.001). ECD independently predicted 3-month death/disability (OR 3.272, 95 % CI 1.670 to 6.413). Conclusions: ECD is prevalent in Chinese patients with acute ischemic stroke. Risk factors include advanced age, stroke severity, and massive cerebral infarct. ECD is associated with higher frequency of stroke-related complications and 3-month death/disability. Keywords: Ischemic stroke, Early consciousness disorder, Occurrence, Risk factor, Complication, Outcome Abbreviations: ECD, Early consciousness disorder; CT, Computed tomography; MRI, Magnetic resonance imaging; mRS, Modified Rankin Scale; NIHSS, National Institutes of Health Stroke Scale; GCS, Glasgow coma scale; ORs, Odds ratios; 95 % CIs, 95 % confidence intervals
Background Stroke is the second most frequent cause of death and the most frequent cause of disability worldwide. In China, stroke has become the leading cause of death and disability in both urban and rural populations, with incidence increasing every year [1]. Approximately 80 % of all strokes are ischemic [1]. Consciousness, which refers to awareness of self and environment, depends on levels of arousal and wakefulness, as well as stimulus content [2]. Many patients in early stages of acute ischemic stroke show acute disorder * Correspondence: [email protected] † Equal contributors 1 Department of Neurology, Stroke Clinical Research Unit, West China Hospital, Sichuan University, No. 37, GuoXue Xiang, Chengdu 610041, Sichuan, People’s Republic of China Full list of author information is available at the end of the article
of consciousness, a condition known as early consciousness disorder (ECD). In fact, stroke is one of the three most frequent causes of conscious disturbance in emergency rooms, together with trauma and hypoglycemia [3]. Data from various stroke registries suggest that 4–38 % of stroke patients experience decreased level of consciousness or coma, and 13–48 % experience confusion or delirium [4–11]. Little is known about the incidence or risk factors of ECD in patients who experience acute ischemic stroke. This is an important question, because early consciousness disorder may disturb physician’ history-taking in clinical practice and ECD in the acute stroke period may predict stroke progression and increase risk of strokeassociated pneumonia [12–14]. Studies have found several possible risk factors of acute disorder of
© 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Li et al. BMC Neurology (2016) 16:140
consciousness after stroke: age, sex, previous stroke, atrial fibrillation, diabetes mellitus, alcohol consumption, stroke severity, infarct sites and, according to some reports, massive cerebral infarct and multiple brain infarcts [15–19]. However, currently available information are rough data extracted from registries for different population. Direct comparative data between stroke patients with ECD and without ECD especially on prospective study are scarce. Further work is needed to identify a reliable set of ECD predictors. Also unclear is whether ECD influences stroke-related complications and clinical outcomes in stroke patients. This is made more important by the fact that the presence of ECD in a stroke patient can affect decisions about treatment and management. To address these questions, the present prospective study analyzed potential ECD risk factors and associated outcomes in a mid-sized cohort of Chinese patients with acute ischemic stroke.
Methods Subjects
Between 1 January 2009 and 31 December 2010, patients with first-ever or recurrent stroke who were admitted to the Department of Neurology at West China Hospital of Sichuan University were consecutively and prospectively registered into the Chengdu Stroke Registry database as described [20]. We enrolled into the present study only those patients who were admitted within 24 h of symptom onset and whose diagnosis of ischemic stroke was confirmed by computed tomography (CT) or magnetic resonance imaging (MRI) of the brain. We excluded patients who had previously received a modified Rankin Scale (mRS) score >2 or who had premorbid conditions such as trauma, intoxication, infection, metabolic or other systemic disease. Baseline assessment
Using a standardized form, we collected patient data at baseline that included age, sex, time between stroke onset and admission, initial stroke severity [assessed using the National Institutes of Health Stroke Scale (NIHSS) score], systolic and diastolic blood pressure, serum glucose concentration, Glasgow coma scale (GCS) score, stroke risk factors and results of neurological imaging. Stroke risk factors in the present study included hypertension, diabetes mellitus, hyperlipidemia, coronary heart disease, atrial fibrillation, valvular heart disease, previous stroke, history of head trauma, current smoking and alcohol consumption [20]. Neurological imaging findings analyzed in this study were where infarcts occurred (frontal, parietal, temporal, occipital and insular lobe, basal ganglia, subcortical white matter, thalamus, brain stem, cerebellum), whether the left or right hemisphere
Page 2 of 7
was involved, and whether the posterior or anterior circulation was involved [21, 22]. Patients in which CT or MRI revealed involvement of more than half the middle cerebral artery distribution were diagnosed as having massive cerebral infarct [23]. Multiple brain infarction was defined as multiple recent infarcts involving non-contiguous regions of abnormality across multiple vascular territories [24]. TOAST criteria were used to assign the likely stroke etiology in each patient as large-artery atherosclerosis, cardioembolism, small-artery occlusion, other determined etiology or undetermined etiology [25]. Conscious state at baseline (initially when admitted to the neurology ward) was independently assessed by two experienced neurologists according to Adams and Victor’s Principles of Neurology (9th edition) [26], via evaluating the patient’s wakefulness, verbal and motor response, orientation to person, place and time, and other physical examination. Patients classified as impaired consciousness (Somnolence, Stupor, Coma, Confusion or Delirium) were assigned to the ECD group, while others were assigned to the no-ECD group. In-hospital and post-discharge outcomes
Hospital staff determined in-hospital stroke-related complications and mortality based on record review after patient discharge or death. At 3 months after stroke onset, patients were contacted for follow-up and asked to fill out a questionnaire during a structured telephone interview or by post. The primary outcomes in this study were in-hospital death and either death or disability during the 3-month follow-up. Disability was defined as an mRS score of 3–5 [27]. Statistical analysis
All statistical analyses were performed using SPSS for Windows 16.0 (IBM, Chicago, IL, USA). Inter-group differences for continuous variables were assessed for significance using Student’s t-test or the Mann-Whitney U test, while differences for categorical variables were assessed using the chi-squared and Fisher exact tests. Multivariate logistic regression by a backward stepwise procedure was used to identify independent risk factors of ECD on admission. Variables were eliminated from the model if their associated P was >0.10. Logistic regression was used to identify independent predictors of 3-month death/disability. When appropriate, effect sizes were estimated using odds ratios (ORs) and 95 % confidence intervals (95 % CIs). All significance levels mentioned are 2-tailed, and the significance threshold was defined as P < 0.05.
Results Between 1 January 2009 and 31 December 2010, 1,506 patients with acute ischemic stroke were consecutively
Li et al. BMC Neurology (2016) 16:140
Page 3 of 7
and prospectively registered in the Chengdu Stroke Registry. Of those, 569 (37.8 %) were admitted to our hospital within 24 h of stroke onset and were therefore included in the present study. Of this group, comprising 303 men and 266 women aged 64.75 ± 14.02 years, 199 (35 %) had ECD on admission, of whom 38 (6.7 %) were Coma. Among the 143 patients in our cohort with hyper-acute ischemic stroke who were admitted within 6 h of symptom onset, ECD occurred in 52 (36.4 %). Among the 81 patients admitted within 4.5 h of symptom onset, ECD occurred in 29 (35.8 %).
ECD and baseline characteristics
Comparison of baseline characteristics of patients with or without ECD (Table 1) showed that those with ECD were older, had higher serum glucose concentrations, higher median NIHSS score and lower median GCS score. Patients with ECD also showed higher rates of several stroke risk factors (coronary heart disease, atrial Table 1 Baseline characteristics of Chinese patients with acute ischemic stroke and with or without early consciousness disorder Patients, n (%)
With ECD
Without ECD P
199 (35.0)
370 (65.0)
——
Mean age, yr
66.7 ± 13.6 63.7 ± 14.2
0.016*
Women, n (%)
103 (51.8)
163 (44.1)
0.079***
Delay from symptom onset to admission, h
13.9 ± 8.2
15.0 ± 8.5
0.130*
Median NIHSS score on admission
16 (0–33)
3.5 (0–19)
RESEARCH ARTICLE
Open Access
Early consciousness disorder in acute ischemic stroke: incidence, risk factors and outcome Jie Li1,2†, Deren Wang1† , Wendan Tao1, Wei Dong1, Jing Zhang1, Jie Yang3 and Ming Liu1*
Abstract Background: Little is known about the incidence and risk factors of early consciousness disorder (ECD) in patients with acute ischemic stroke, or about how ECD may affect complications and outcomes. Methods: Patients admitted to our hospital within 24 h of onset of acute ischemic stroke were consecutively enrolled. ECD was evaluated clinically and using the Glasgow coma scale. Multivariate analysis was used to identify risk factors of ECD, as well as associations between ECD and clinical outcomes. Results: Of the 569 patients enrolled, 199 (35 %) had ECD. Independent risk factors of ECD were advanced age (OR 1. 027, 95 % CI 1.007 to 1.048), National Institutes of Health Stroke Score on admission (OR 1.331, 95 % CI 1.257 to 1.410), and massive cerebral infarct (OR 3.211, 95 % CI 1.642 to 6.279). ECD was associated with higher frequency of strokerelated complications (83.4 % vs. 31.1 %, P < 0.001) and higher in-hospital mortality (17.1 % vs. 0.5 %, P < 0.001). ECD independently predicted 3-month death/disability (OR 3.272, 95 % CI 1.670 to 6.413). Conclusions: ECD is prevalent in Chinese patients with acute ischemic stroke. Risk factors include advanced age, stroke severity, and massive cerebral infarct. ECD is associated with higher frequency of stroke-related complications and 3-month death/disability. Keywords: Ischemic stroke, Early consciousness disorder, Occurrence, Risk factor, Complication, Outcome Abbreviations: ECD, Early consciousness disorder; CT, Computed tomography; MRI, Magnetic resonance imaging; mRS, Modified Rankin Scale; NIHSS, National Institutes of Health Stroke Scale; GCS, Glasgow coma scale; ORs, Odds ratios; 95 % CIs, 95 % confidence intervals
Background Stroke is the second most frequent cause of death and the most frequent cause of disability worldwide. In China, stroke has become the leading cause of death and disability in both urban and rural populations, with incidence increasing every year [1]. Approximately 80 % of all strokes are ischemic [1]. Consciousness, which refers to awareness of self and environment, depends on levels of arousal and wakefulness, as well as stimulus content [2]. Many patients in early stages of acute ischemic stroke show acute disorder * Correspondence: [email protected] † Equal contributors 1 Department of Neurology, Stroke Clinical Research Unit, West China Hospital, Sichuan University, No. 37, GuoXue Xiang, Chengdu 610041, Sichuan, People’s Republic of China Full list of author information is available at the end of the article
of consciousness, a condition known as early consciousness disorder (ECD). In fact, stroke is one of the three most frequent causes of conscious disturbance in emergency rooms, together with trauma and hypoglycemia [3]. Data from various stroke registries suggest that 4–38 % of stroke patients experience decreased level of consciousness or coma, and 13–48 % experience confusion or delirium [4–11]. Little is known about the incidence or risk factors of ECD in patients who experience acute ischemic stroke. This is an important question, because early consciousness disorder may disturb physician’ history-taking in clinical practice and ECD in the acute stroke period may predict stroke progression and increase risk of strokeassociated pneumonia [12–14]. Studies have found several possible risk factors of acute disorder of
© 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Li et al. BMC Neurology (2016) 16:140
consciousness after stroke: age, sex, previous stroke, atrial fibrillation, diabetes mellitus, alcohol consumption, stroke severity, infarct sites and, according to some reports, massive cerebral infarct and multiple brain infarcts [15–19]. However, currently available information are rough data extracted from registries for different population. Direct comparative data between stroke patients with ECD and without ECD especially on prospective study are scarce. Further work is needed to identify a reliable set of ECD predictors. Also unclear is whether ECD influences stroke-related complications and clinical outcomes in stroke patients. This is made more important by the fact that the presence of ECD in a stroke patient can affect decisions about treatment and management. To address these questions, the present prospective study analyzed potential ECD risk factors and associated outcomes in a mid-sized cohort of Chinese patients with acute ischemic stroke.
Methods Subjects
Between 1 January 2009 and 31 December 2010, patients with first-ever or recurrent stroke who were admitted to the Department of Neurology at West China Hospital of Sichuan University were consecutively and prospectively registered into the Chengdu Stroke Registry database as described [20]. We enrolled into the present study only those patients who were admitted within 24 h of symptom onset and whose diagnosis of ischemic stroke was confirmed by computed tomography (CT) or magnetic resonance imaging (MRI) of the brain. We excluded patients who had previously received a modified Rankin Scale (mRS) score >2 or who had premorbid conditions such as trauma, intoxication, infection, metabolic or other systemic disease. Baseline assessment
Using a standardized form, we collected patient data at baseline that included age, sex, time between stroke onset and admission, initial stroke severity [assessed using the National Institutes of Health Stroke Scale (NIHSS) score], systolic and diastolic blood pressure, serum glucose concentration, Glasgow coma scale (GCS) score, stroke risk factors and results of neurological imaging. Stroke risk factors in the present study included hypertension, diabetes mellitus, hyperlipidemia, coronary heart disease, atrial fibrillation, valvular heart disease, previous stroke, history of head trauma, current smoking and alcohol consumption [20]. Neurological imaging findings analyzed in this study were where infarcts occurred (frontal, parietal, temporal, occipital and insular lobe, basal ganglia, subcortical white matter, thalamus, brain stem, cerebellum), whether the left or right hemisphere
Page 2 of 7
was involved, and whether the posterior or anterior circulation was involved [21, 22]. Patients in which CT or MRI revealed involvement of more than half the middle cerebral artery distribution were diagnosed as having massive cerebral infarct [23]. Multiple brain infarction was defined as multiple recent infarcts involving non-contiguous regions of abnormality across multiple vascular territories [24]. TOAST criteria were used to assign the likely stroke etiology in each patient as large-artery atherosclerosis, cardioembolism, small-artery occlusion, other determined etiology or undetermined etiology [25]. Conscious state at baseline (initially when admitted to the neurology ward) was independently assessed by two experienced neurologists according to Adams and Victor’s Principles of Neurology (9th edition) [26], via evaluating the patient’s wakefulness, verbal and motor response, orientation to person, place and time, and other physical examination. Patients classified as impaired consciousness (Somnolence, Stupor, Coma, Confusion or Delirium) were assigned to the ECD group, while others were assigned to the no-ECD group. In-hospital and post-discharge outcomes
Hospital staff determined in-hospital stroke-related complications and mortality based on record review after patient discharge or death. At 3 months after stroke onset, patients were contacted for follow-up and asked to fill out a questionnaire during a structured telephone interview or by post. The primary outcomes in this study were in-hospital death and either death or disability during the 3-month follow-up. Disability was defined as an mRS score of 3–5 [27]. Statistical analysis
All statistical analyses were performed using SPSS for Windows 16.0 (IBM, Chicago, IL, USA). Inter-group differences for continuous variables were assessed for significance using Student’s t-test or the Mann-Whitney U test, while differences for categorical variables were assessed using the chi-squared and Fisher exact tests. Multivariate logistic regression by a backward stepwise procedure was used to identify independent risk factors of ECD on admission. Variables were eliminated from the model if their associated P was >0.10. Logistic regression was used to identify independent predictors of 3-month death/disability. When appropriate, effect sizes were estimated using odds ratios (ORs) and 95 % confidence intervals (95 % CIs). All significance levels mentioned are 2-tailed, and the significance threshold was defined as P < 0.05.
Results Between 1 January 2009 and 31 December 2010, 1,506 patients with acute ischemic stroke were consecutively
Li et al. BMC Neurology (2016) 16:140
Page 3 of 7
and prospectively registered in the Chengdu Stroke Registry. Of those, 569 (37.8 %) were admitted to our hospital within 24 h of stroke onset and were therefore included in the present study. Of this group, comprising 303 men and 266 women aged 64.75 ± 14.02 years, 199 (35 %) had ECD on admission, of whom 38 (6.7 %) were Coma. Among the 143 patients in our cohort with hyper-acute ischemic stroke who were admitted within 6 h of symptom onset, ECD occurred in 52 (36.4 %). Among the 81 patients admitted within 4.5 h of symptom onset, ECD occurred in 29 (35.8 %).
ECD and baseline characteristics
Comparison of baseline characteristics of patients with or without ECD (Table 1) showed that those with ECD were older, had higher serum glucose concentrations, higher median NIHSS score and lower median GCS score. Patients with ECD also showed higher rates of several stroke risk factors (coronary heart disease, atrial Table 1 Baseline characteristics of Chinese patients with acute ischemic stroke and with or without early consciousness disorder Patients, n (%)
With ECD
Without ECD P
199 (35.0)
370 (65.0)
——
Mean age, yr
66.7 ± 13.6 63.7 ± 14.2
0.016*
Women, n (%)
103 (51.8)
163 (44.1)
0.079***
Delay from symptom onset to admission, h
13.9 ± 8.2
15.0 ± 8.5
0.130*
Median NIHSS score on admission
16 (0–33)
3.5 (0–19)
